Junction boxes are used for connecting the electrical harnesses as fitted in particular to airplanes, and for electrically configuring such airplanes without modifying existing electrical harasses, thus making it possible to obtain wiring that matches the requirements of customers.
Conventionally, in aviation, cable systems are used that make use of harnesses of electric wires. Harnesses are made up on demand as a function of customer requirements. They therefore differ from one airplane to another, depending on specific needs, and they contain a large number of branch connections. Cross-connections between different harnesses are thus established at disconnection terminals that are concentrated at the boundaries between airplane segments.
In order to simplify the fabrication of harnesses, it has been found to be preferable, in particular in the field of helicopters, to concentrate branch connections and cross-connections between terminals within junction boxes. These junction boxes can be made either by juxtaposing special small harnesses or else by the wire-wrapping technique. Wiring such junction boxes can then become very complex. Such wiring is heavy, bulky, expensive, and differs from one aircraft to another.
Recently, it has been found advantageous to use ribbon cables of wires instead of conventional harnesses of wires. This means that it is not possible to implement cross-connections within connectors, since the wires are ordered, and this also makes it difficult to establish branch connections.